There are several chunk style dry animal food products on the market today which are particularly appealing to the consumer due to their shelf stability and convenience. These products are specifically formulated using proteinaceous and/or farinaceous source ingredients, and are characterized by a porous structure and crunchy texture. These products may be served as is or may be rehydrated with water prior to consumption by the dog or cat. The palatability of these products is further enhanced by a coating of fat on the surface of the chunk or kib, over which coating may be applied a powdered gravy forming material based on gums, starches, coloring and flavoring material. Upon hydration, the gravy forming material serves to thicken and color the water thereby simulating a gravy or meat sauce.
Such products may be manufactured by preparing a mixture of farinaceous and/or proteinaceous ingredients with optional vitamin and mineral supplements, said mixture having a moisture content within the range of about 20 to 40% by weight. This mixture is processed by heating it above about 212.degree. F and subjecting it to superatmospheric pressure and masceration such as in an extruder, and extruding it through an extrusion die into the atmosphere. As the material issues from the die it expands into a porous, expanded product due to the pressure drop across the die and the flashing off of the water as steam. The extrudate is then cut into bite size kibs having a mean diameter within the range of about 1/4 to 3/4 inch, dried to a moisture content of less than about 10% by weight, coated with fat and optionally a powdered gravy forming ingredient, and packaged. Examples of such products and the methods for preparing them may be found in U.S. Pat. Nos. 3,119,691 and 3,447,929.
Kennel studies show that the aforementioned products have greater appeal to the pet when served mixed with water. However, due to the porous nature of the product, the kibs rapidly absorb water such that in a period of five minutes or so the kibs have lost much of their crunchy texture, particularly attractive to dogs, and become soggy or mushy. Thus, a certain amount of waste and inconvenience to the consumer may be encountered unless the hydrated kibs are consumed by the pet quickly after serving.
Accordingly, it is an object of this invention to prepare a hydratable animal food product which retains its crunchy and crispy texture for longer periods of time when served with water.
A further object of this invention is to prepare a hydratable animal food of improved palatability which exhibits an improved resistance to quick wetting and also the tendency to become mushy or soggy after periods of exposure to water.